Smartphone Battery Cases: OtterBox iON for iPhone 4/4s $40 (Reg. $130), uNu ultra-slim for Galaxy S4 $39 (Reg. $69)

Tack on extra battery life to your iPhone or Galaxy S4 with two new offers from Groupon and BuyDig:

OtterBox Defender Series iON for iPhone 4/4s: $39.99 with free shipping (Reg. $70) at Groupon. It features three layers of protection again drops, a built-in screen protector, and 1450mAh lithium-ion battery. The free iON Intelligence battery app analyzes past usage patterns to estimate remaining battery life (in hours/minutes). 9to5mac reviewed this case back when it was selling for upwards of $130 and was happy with its performance:

…But for days when you need extra power, and/or are at greater risk of dropping it (like holding it by a bicycle wheel while cycling fast downhill on a bumpy road, to pick a completely random example …), it does the job it was designed for perfectly.

If you need some juice for your iPhone 5/5s, then head over to Amazon where you can get the uNu Power DX MFi Lightning case for $49.99. It’s temporarily out of stock but will ship as soon as it’s available.

uNu Unity Ultra-Slim for Samsung Galaxy S4: $39 with free shipping – coupon code SP1 (Reg. $69). It features a 2600mAh battery, slim design, and added protection against drops. Available in multiple colors. You can pickup cheaper battery cases on Amazon, but we recommend sticking with high-quality power gear to keep your internal battery as healthy as possible. Rated 4.4 out of 5 stars.

uNu Unity Ultra-Slim 2600mAh Battery Case for Samsung Galaxy S4 – Black/Black

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